MANILA, Aug. 18 (Xinhua) -- The A/H1N1 influenza is expected to become the dominating strain in the North Hemisphere's upcoming winter, crowding out normal seasonal flu and causing more deaths, said a regional spokesman of the World Health Organization (WHO) on Tuesday.

    "The virus is unstoppable now. It's inevitable that we are going to see more infected cases, and unfortunately more deaths, as the North enters winter," John Larking, communication specialist of the WHO Western Pacific Region, told Xinhua in an interview on Tuesday.

    Influenza normally takes off in winter months. Australia, Argentina, Chile and other South Hemisphere countries all experienced a spike of A/H1N1 flu cases and related deaths in the past winter.

    Larking said the WHO has been officially notified of 50 A/H1N1 influenza-related deaths in the Western Pacific region which covers East and Southeast Asia and Oceania, but the combined fatality counts by the region's health authorities have mounted to169 by Aug. 12, according to the WHO website.

    Though a mild pandemic, the A/H1N1 influenza has shown able to cause serious illness and death among certain groups of people, Larking said, and developing countries with an under-resourced health system but large number of poor people will face extra challenges.

    The vaccines can only be available for several countries by September and there is always possibility that the virus might mutate into a more dangerous strain, Larking said.

    In the absence of vaccines, one lessen that can be learnt from the South's battle with A/H1N1 is that people who belong to the high risk group should seek treatment early, best within 48 hours after they fall ill. Patients who developed serious complications or died often sought treatment too late, Larking said.

    The WHO considers people with cancer, HIV/AIDS, chronic respiratory conditions, cardiac disease, diabetes, might be higher risk to the A/H1N1 influenza, along with pregnant women, the morbidly obese, and smokers.

    Seven countries in the region with high maternal mortality rates -- Cambodia, Laos, Papua New Guinea, the Philippines, Vietnam, Mongolia and China -- face greater risks of the pandemic.

    Larking said the start of a school year might also be an issue but the WHO does not make "fast and hard" recommendations on school closures. Also left to national governments' discretion are their response strategies.

    Though several countries in the region have shifted from containment to a mitigation phrase in response to the pandemic, which means they no longer test all suspected cases and focus more on treatment, Larking said there is no a universal strategy shift recommendation from the WHO.

Special Report:  World Tackles A/H1N1 Flu